Can't help with supplying one but do bear in mind that the column, headstock and milling bracket have two distinct versions. AFAIK you can't mix and match.

The earlier column has a tapered hole straight through the middle of the spigot into which a bolt with a tapered section screws. The later one has a groove (or is it two?) all around the circumference of the spigot.

My Uni has the earlier style... which is why I'm a bit vague on the later style.

On Wed, 22 Mar 2023 at 20:30, Andy Carlson

<andycarlson@...> wrote:

Can't help with supplying one but do bear in mind that the column, headstock and milling bracket have two distinct versions. AFAIK you can't mix and match.

The earlier column has a tapered hole straight through the middle of the spigot into which a bolt with a tapered section screws. The later one has a groove (or is it two?) all around the circumference of the spigot.

My Uni has the earlier style... which is why I'm a bit vague on the later style.

Hi all, I'm considering? ER16 / ER20 / ER25 collet holder for my PC/Basic vertical mill.

Couple of questions:

- Is a larger collet holder better for accuracy (eg. larger = less runout?)

- Is there a endmill size that is "too large" for a stock U3 (and / or PC/Basic) given the smallish motor??

If 12mm is unfeasible, then ER25 doesn't make as much sense as an ER25.

?

Thanks!

JP

I did something like this a while back, when I built a bench specifically for making miniature parts for an F1 team. I was aiming to use my SL & U3 lathes, plus the little Proxxon mill. I made a cubby hole under the bench with wooden rails both sides to act as drawer runners. I made some wooden bases to fit on these runners, and bolted my machines to them. I added steel equipment handles which bolted right through the bases, so were unlikely to come unstuck. I made the bases of ?" MDF, because I had lots of it lying around, left over from constructing kitchen cabinets (or something like that). I also used them to build the bench, with a bit of kitchen worktop - on top. I could then put away all three machines under the bench leaving the top clear for hand work. I did find I had just enough room to get two machines running side by side.

Lessons to learn. The boards were based on the size of the SL, which has now gone off to Australia. This was big enough for the Proxxon mill, but for the U3 it was a tight fit. As for my PC/Basic, that came later and is definitely not going to fit. One day, when I am feeling strong I will modify the bench and make bigger machine bases. I will also add small racks, maybe just blocks with useful sized holes in them, to keep things like tommy bars, hex & chuck keys close by. For machines with 24 V motors and speed controls I might put the controllers on the boards so they are convenient to reach, but leave the 24 V power supply elsewhere so there is no high voltage on the board.

One day when I can dig my way back into the garage I will take some pictures so folks can see what I mean, and decide whether it is the sort of thing they need.

As for the base, use good quality wood. I would look for good quality ply, with a nice smooth surface. Round off the corners, sand the edges and maybe seal with. Consider adding a lip round the edge paint or varnish so small parts will not fall off. If the boards slide around on your bench get some large rubber feet or add some pads of sheet rubber to provide grip. For suitable handles go to a local hardware shop and look at some of the bigger door and drawer handles. Get something chunky, but remember, not so big it blocks access to the lathe.

Think ahead, and plan it out on a big sheet of paper on the bench. Then you will find the things you forgot about are not so important.